New to this forum. I previously downloaded Ebooks and converted them
with Calibre to MOBI.

I recently reformatted my computer and reinstalled Calibre 8.41
upon viewing my MOBI Ebook all worked find however I noticed that
the MOBI icon on each book changed from a Blue book looking Icon to a stack of horizontal books, somewhat like Cailbre's application and desktop
icon. Only mine is white with colored books.

I then deleted Ver 8.41 and tried ver 8.21, the one I used orginally.
I got the same Icon with both versions.